One-pot sequential aldol condensation and hydrodeoxygenation of furfural and acetone to 1-octanol over multifunctional acid-based catalytic system

Abstract

Furfural and acetone are two of the most promising chemicals derived from lignocellulosic biomass. Coupling these two compounds expands the broad range of value-added chemicals that can be derived from biomass. In this study, 1-octanol, a promising medium chain-length alcohol, was produced from furfural and acetone through a series of reactions: aldol condensation (R1), hydrogenation (R2), and hydrogenolysis (R3). Each step was individually investigated to understand its mechanism and requirements, enabling seamless integration into one-pot, two-step (R1, R2 + R3) and one-pot, three-step (R1 + R2 + R3) processes. To facilitate these reactions, bifunctional alumina–zirconia-based catalysts were synthesized. Additionally, to enhance the yield of 1-octanol, solid acidic additives, particularly sulfonic acid-functionalized silica (KCC-1-APSO₃H), were incorporated into the reaction. The highest yield of 1-octanol (69.1 %) was achieved with the three-step process (R1, R2, R3), followed by the one-pot, two-step process (R1, R2 + R3, 64.8 %), and the one-pot, three-step process (R1 + R2 + R3, 48.7 %) using the combined Ni/Al₂O₃-ZrO₂ and KCC-1-APSO₃H catalyst. Among all the processes investigated, the one-pot, two-step process emerged as the best approach balancing the efficiency of the process integration and 1-octanol yield. The present study offers valuable insights into the development of catalytic methods for producing linear alcohols from biomass.